Thymosin Alpha 1: Sustained T-Helper Count Rise in Three-Drug Combination

An Italian study has found that a three-drug combination of
AZT, alpha interferon, and thymosin alpha 1
resulted in a large increase in T-helper cell count,
sustained for at least 18 months, in patients who started
with a T-helper count between 200 and 500. However, only a
handful of patients received the treatment in this small,
preliminary study; and no one in either the treatment or the
control arms progressed to AIDS, so there is no proof yet
that the treatment resulted in clinical benefit. A larger
study has started in Italy.

Thymosin alpha 1, a thymic hormone which affects the
maturation of T-cells, has been developed primarily as a
treatment for hepatitis B and C; in the U.S., it is an orphan
drug being developed by Alpha 1 Biomedicals, Inc., of
Bethesda, Maryland. It was first considered as a possible
AIDS treatment at least ten years ago.

In the new study, volunteers were given 500 mg per day of
AZT, 2 million units of natural human alpha interferon
(Wellferon) intramuscularly twice weekly, and 1 mg of
thymosin alpha 1 subcutaneously twice weekly. Of the seven
patients who completed one year of the three-drug treatment,
the average T-helper count went from 309 before treatment to
496 after treatment. This difference was statistically
significant (p = 0.029), meaning that it would have been
unlikely to have occurred by chance alone.

Five of these patients continued treatment through 18 months
on the three drugs; their average T-helper counts increased
by 50 between month 12 and month 18. (This difference was not
statistically significant, however, since the standard
deviation of both averages was over 200.)

Incidentally, the two-drug combinations of AZT plus alpha
interferon, or AZT plus thymosin alpha 1, seemed to work much
less well than the three-drug combination, although better
than AZT alone.

Reference

Garaci E, Rocchi G, Perroni L, and others. Combination
treatment with zidovudine, thymosin alpha 1, and interferon-alpha
in human immunodeficiency virus infection. INTERNATIONAL
JOURNAL OF CLINICAL & LABORATORY RESEARCH. 1994;
volume 24, pages 23-28.